New Jersey, in fairness, is a tricky state for jobs. Many Garden State folks work in New York or Philadelphia; the state government can only do so much. But if the jobs picture is complex, the fiscal disaster is made to order in Trenton (seat of the Christie administration).

Christie's ludicrous budget, which he touted at the convention as a model of good governance, relied on an annual growth projection of 7.2%, higher than anywhere in the nation save California. Some might call that optimistic, others downright fantastical.

Not only is projected growth coming in below that figure, by nearly a point, but even if growth had met Christie's target, that would still leave the state short $258m, thanks to across-the-board corporate tax cuts. There was never anything balanced about Christie's "three balanced budgets with lower taxes", as he called them at the convention. And Jersey, it's now clear, is not coming back from anywhere.

The Christie juggernaut is finally facing a backlash. And so the governor's trademark petty insults are now directed not only at his political opponents, but at anyone who even mentions that things are going south. Both the media and Democrats are "rooting for failure" if they point up that unemployment is up and revenues are down. And when the head of the state's nonpartisan office for budget analysis identified the massive revenue shortfall, Christie responded in typically furious fashion. "Why would anyone with a functioning brain believe this guy?" he yowled, before comparing him to Dr Kevorkian.

To anyone surprised by Christie's absurd governance and indifference to economics, all I can say is that this is nothing new. Christie first trumpeted his arrival on the national scene by cancelling, at the height of Tea Party anti-government fervor, the largest public works project anywhere in the United States: a vital new tunnel under the Hudson River 20 years in the making. The project had already broken ground when the governor unilaterally shut it down, fearing that basic, sorely-needed infrastructure would put state taxpayers on "a never-ending hook". (What does a never-ending hook look like?)

Yet, according to a report this April by the Government Accountability Office, Christie had grossly exaggerated New Jersey's liability for the tunnel. He said the state would have to foot 70% of the bill; it was really under 15%. The governor had railed that costs were spiraling out of control; actually, they were unchanged for several years. Naturally, though, the governor was unmoved by this nonpartisan budget analysis. When it comes to public works, whatever the figures say, "no matter how much the administration yells and screams, you have to say no."

It was classic Christie to couch his ruthlessness on the tunnel project in the language of "tough calls" and "hard choices" – a theme he returned to in his recent convention speech, where he laughably opined that politicians have "become paralyzed by our desire to be loved". To every self-serving dismissal you can trust Christie to impute the highest degree of righteousness. (In this, he has a friend in Paul Ryan, who likes to insist that his oligarchical deception of massive tax cuts and the gutting of every public sector program outside the military is a "moral imperative" for "our children and our grandchildren".)

But what tough call did Christie make with the Jersey cash earmarked for the tunnel? He put it into a transportation fund so he could keep the state gas tax at an absurdly low rate – the third-lowest rate in the nation, less than half that of New York, and unchanged since 1988. Critically important infrastructure or a couple of pennies less on a tank of unleaded? As he says, it's a tough call.

Enough, you might think, to make a New Jersey voter miss Jim McGreevey and Bob Toricelli, the state's former champions of political malfeasance. And yet, such is the condition of American politics that this man – who, in case you forgot, also has trailing behind him the voluminous baggage of abuse of power scandals that would spell doom for most politicians – remains the presumed standard-bearer for the Republican party in 2016.

He is a smart enough political operator to know that the Romney campaign is capsizing. He denies reports that he turned down the VP slot out of fear of failure, but during his impressively self-serving keynote address at the GOP convention, he failed to mention Romney until 16 minutes into a 24-minute speech. His approval ratings remain high in reliably blue territory, and more than half of New Jerseyans say their traumatized state is heading in the right direction.

So what Christie, and we, are learning is that he doesn't need Romney or anyone else to succeed. He doesn't need to be a successful governor, or even a minimally competent one. Fill the role demanded by central casting – the hard-driving tax-slasher with no time for niceties – and there will be enough insulation, in the party and in the media, to withstand even the most dismal economic performance. He may be a bully rather than a leader, but Christie is savvy enough to know which gets to you to the top.